Antioxidant activities of natural 9-cis β-carotene of Donliella bardawil on human neutrophil ROS production

β -胡萝卜素几何异构体的生物活性一直是人们关注的焦点。本研究采用人中性粒细胞化学发光法，在调理酶酶酶的刺激下，研究了从多纳氏菌中纯化的天然9-顺式β-胡萝卜素和合成的全反式β-胡萝卜素的体外抗氧化活性。采用lucigenin依赖性化学发光法大量测定超氧阴离子（O_2）的产生，采用氮化钠（NaN_3）和辣根过氧化物酶（HRP）的依赖性化学发光法测定过氧化氢（H_2O_2）的产生，采用无氧化代谢调节剂的依赖性化学发光法测定髓过氧化物酶（MPO）介导的产生。在β-胡萝卜素浓度为1.4 μM时，中性粒细胞对天然9-顺式β-胡萝卜素和合成全反式β-胡萝卜素的依赖性化学发光分别降低了对照组的75%和78% （P<0.05）。当β-胡萝卜素浓度为1.86 μM时，中性粒细胞在NaN_3和HRP的作用下，鲁米诺依赖性化学发光也分别下降到天然9-顺式β-胡萝卜素和合成全反式β-胡萝卜素的86%和81% （P< 0.05）。另一方面，在相同浓度的天然9-顺式β -胡萝卜素和人工全反式B -胡萝卜素的化学发光实验中，中性粒细胞没有统计学上的显著差异。结果表明，在1.86μM浓度下，天然9-顺式B -胡萝卜素与合成全反式β -胡萝卜素的抗氧化活性相当。

Much attention has been focused on the biological activity of geometrical isomers of β -carotene. In the present study, the in vitro antioxidant activities of a natural 9-cisβ-carotene purified from Donaliella bardawil and synthetic all-transβ -carotene were studied using enhanced human neutrophil chemiluminescence upon stimulation with opsonized zymosan. Lucigenin-dependent chemiluminescence was used for largely measuring superoxide anion (O_2) production, luminal-dependent chemiluminescence with sodium azide (NaN_3) and horseradish peroxidase (HRP) was used for measuring hydrogen peroxide (H_2O_2) production, and luminal-dependent chemiluminescence without oxidant metabolism modulator was used for determination of myeloperoxydase (MPO)-mediated production. With β -carotene concentration of 1.4 μM, neutrophils showed a decrease in lucigenin-dependent chemiluminescence to 75 % and 78 % of controls (P<0.05) by natural 9-cis β -carotene and synthetic all-trans β-carotene, respectively. With β-carotene concentration of 1.86 μM, neutrophils also showed a decrease in luminol-dependent chemiluminescence in the presence of NaN_3 and HRP to 86 % and 81 % of controls (P< 0.05) by natural 9-cis β -carotene and synthetic all-trans β-carotene, respectively. On the other hand, neutrophils did not show a statistically significant difference in any chemiluminescence assay by the same concentration of natural 9-cis β -carotene and synthetic a all-trans B -carotene. These results suggest that, up to the concentration of 1.86μM, natural 9-cis B -carotene and synthetic all-trans β -carotene exert equal antioxidant activities assessed by enhanced human neutrophil chemiluminescence.